A tremendous number of morels grow in Oregon, primarily in coniferous forests. It can sometimes be a little tricky to go out at the right time to find them, though. Knowing what conditions they thrive in is a key to knowing when to hunt for morel mushrooms in Oregon.
The fruiting body of the morel, the part we know as morel mushrooms, is only a small part of the whole. Tiny spores can lay dormant in the soil for months or even years, until the conditions are right. They then produce thousands of hair-like roots that spread in all directions. When they've received enough nourishment, and again when conditions are right, the fruiting head is produced.
For this to happen, there needs to be adequate moisture, plenty of sunshine, and the ground temperature needs to be high enough for the tiny roots to grow. For this reason, they tend to appear as snow line recedes and the air grows warmer.
In many of the mountainous regions of Oregon, this usually occurs between the last week in May to the first week in June, but it can vary depending on the amount of snow and how long it takes for the weather to warm up and the snow to recede.
Part of the trick of knowing when to hunt them is being very aware of the weather conditions. In years that become hot too fast, the soil can dry out, and morel season will be short. In years when there is plenty of moisture and the air temperatures remain steady at around 70 degrees Fahrenheit during the day, the morel mushroom season may last over a month.
This means that sometimes the mushroom season is early, and other times it is late. For instance, May and June of 2009 were cooler and wetter than normal for all of Oregon, so most morels were found a bit later than normal. In 2003, conditions were nearly ideal for a prolonged amount of time. That year, one family of four, two adults and two children, filled three 5-gallon buckets with morels in about 4 hours. This was on the first weekend in June of that year, and they happened to be camping in an area that produces large quantities of morels in most years.
They knew the signs to look for. The air temperature was right and was steady, with cool nights and moderate days. The snow line had receded, yet small patches of snow could still be found in isolated locations. In many places the ground appeared to be dry, yet it was still damp an inch or two under the surface (a little less than a centimeter).
While they didn't go out camping in that area specifically to hunt morels, they knew that they'd selected the right time, when they found a couple of morels growing in camp, before even unpacking for camp set up. They even found a few giant puffball mushrooms.
The best bet is to be aware of the weather at the location you are going to be hunting morels. The last part of May to the first part of June is a handy figure, but always remember that this will change according to the weather conditions. Also, remember that the higher the elevation, probably the later the morel season is going to be. Further, note that in some years, conditions again become right in the early fall, and morels can be found then as well, though usually not in the same profusion as in the spring. The mushrooms also tend not to be quite as large.
In Oregon and many other locations, knowing when to hunt for morel mushrooms is what leads to success. However, this is less of a matter of a calendar date, and more of a case of observing the weather. If you are lucky, you can do what the family managed. What would you do with 15 gallons of wonderful, fresh, tasty morels?